<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link href="//cdn.bootcss.com/chosen/1.6.2/chosen.css" rel="stylesheet">
</head>

<body>
    <select name="demo" id="demo" style="width: 300px">
        <option value="1">1</option>
        <option value="2">2</option>
        <option value="3">3</option>
        <option value="4">4</option>
    </select>
    <br>
    <br>
    <select name="demo2" id="demo2" multiple data-placeholder="请选择...">
        <option value="1">1</option>
        <option value="2">2</option>
        <option value="3">3</option>
        <option value="4">4</option>
    </select>
    <script src="../../../vendor/jquery-1.12.4.js"></script>
    <script src="//cdn.bootcss.com/chosen/1.6.2/chosen.jquery.js"></script>
    <script>
    $(function() {
        $('#demo').chosen();
        $('#demo2').chosen({
            width: '50%'
        });
    });
    </script>
</body>

</html>
